The expression of Angıotensin 1-Converting Enzyme and Hipoxia Inducible Factor in colonic adenomas and adenocarcinomas

The Angiotensin I?Converting Enzyme (ACE), hypoxia-inducible factors (HIF-1 and HIF-2) are important in the processes of angiogenesis and tumor growth. In our prospective study we measured the overexpression of ACE and HIF-1? and HIF-2? immunohistochemically in various types of colonic adenomas and investigate the differences from the normal and cancerous tissues.Five groups composed from normal mucosal, tubular (TA), tubulovillous (TVA) and villous adenomas (VA) and colorectal carcinomas (CRCs) (n=10) included to the study.Grade 3 ACE expressions were detected in all tumor epithelial cells and endothelial cells. In only one TA and two TVA focal ACE expression and in three VA Grade 2 ACE expressions was detected. ACE, HIF-1? and HIF-2? expressions were not expressed by nonneoplastic colon epithelium. Diffuse expressions of HIF-1? and HIF-2? were present in all CRCs (%100). HIF-1? expression was highest in VA, detected in 40%, 50%, 80% of the adenomatous epithelia in TA, TVA and VA, respectively. Among the adenoma types, HIF-2? expression in the neoplastic epithelia did not show any difference. Focal expression in 80% of TA, 75% of TVA, 80% of VA was detected. However in all adenomas focal HIF-2? expression was detected in lymphocytes mainly located in villous areas and/or in high dysplastic areas where as the density of HIF-2? (+) lymphocytes and the adenoma types were correlated.In our study, although there was rare ACE expression in adenoma cases, the expression was highest in the villous adenomas. HIFs are found in both adenoma and carcinoma. Those findings suggest the role of ACE and HIFs in adenoma-carcinoma sequence. Those can be due to role of ACE and HIFs on angiogenesis. The correlation with the HIF-2? positive lymphocytes and the adenoma type suggests that HIF-2? related cytokines can have an important role.Key Works: ACE-1,HIF 1?,HIF 2?,Colon adenomas,Colon carcinomas,immünohistochemistry